Connecting Power to a DC-Powered M320 Router

You connect DC power to the router by attaching power cables from the DC power sources to the terminal studs on the power supply faceplates. To connect power to the router, you must provide grounding and power cables (the cable lugs are supplied with the router). For grounding and power cable specifications, see M320 Chassis Grounding Cable and Lug Specifications and M320 DC Power Cable Specifications.

Caution: You must ensure that power connections maintain the proper polarity. The power source cables might be labeled (+) and (–) to indicate their polarity. There is no standard color coding for DC power cables. The color coding used by the external DC power source at your site determines the color coding for the leads on the power cables that attach to the terminal studs on each power supply.

To connect the DC source power cables to the router, for each power supply:

1. Ensure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cable leads might become active during installation.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to an approved site ESD grounding point.
3. Verify that the source power cabling and the grounding cabling are correct, that they are not touching or blocking access to router components, and that they do not drape where people could trip on them.
4. Switch the circuit breaker on the DC power supply faceplate to the off position (O).
5. Remove the clear plastic cover protecting the terminal studs on the faceplate.
6. Remove the nut and washer from each power terminal stud. If no washers and nuts are already installed, they should be in the accessory box.
7. Attach the lugs on the DC source power cables to the terminal studs.
   1. Attach the lugs on the positive (+) DC source power cables to the terminal studs.
   2. Attach the lugs on the negative (–) DC source power cables to the terminal studs.

   Secure each cable lug to the terminal stud, first with a washer, then with a nut. Use a 7/16-in. (11 mm) nut driver or wrench to tighten the nut. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.

   Note: The DC power supplies in slots PEM0 and PEM1 must be powered by dedicated power feeds derived from feed A, and the DC power supplies in slots PEM2 and PEM3 must be powered by dedicated power feeds derived from feed B. This configuration provides the commonly deployed A/B feed redundancy for the system.

8. Loosen the captive screw on the cable restraint on the right edge of the power supply faceplate.
9. Route the positive and negative DC power cables through the top and bottom of the cable restraint.
10. Tighten the cable restraint captive screw to hold the power cables in place.
11. Verify that the power cabling is correct, that the power cables do no touch or blocki access to Routerrouter components, or drape where people could trip on them.
12. Replace the clear plastic cover over the terminal studs on the faceplate.

Figure 1: Connecting DC Power to the M320 Router